1.(2X+Y)的2次方-(2X-Y)(X+Y)-2(X-2Y)(X+2Y)2.(X+2Y)的2次方-2(X-Y)(X+Y)+2Y(X-3Y)

问题描述:

1.(2X+Y)的2次方-(2X-Y)(X+Y)-2(X-2Y)(X+2Y)
2.(X+2Y)的2次方-2(X-Y)(X+Y)+2Y(X-3Y)

1.(2X+Y)^2-(2X-Y)(X+Y)-2(X-2Y)(X+2Y)解原式=4X^2+Y^2+4XY-2X^2-2XY+XY+Y^2-2(X^2-4Y^2)=4X^2+Y^2+4XY-2X^2-2XY+XY+Y^2-2X^2+8Y^2=4X^2-2X^2-2X^2+Y^2+Y^2+8Y^2+4XY-2XY+XY=10Y^2+3XY2.(X+2Y)^2-2(X-Y...